x=int(input("请输入本月国内通话时长:"))
y=int(input("请输入本月短信条数:"))
z=int(input("请输入本月已用数据流量:"))
if x<=250 and y<=100 and z<=50:
    print("本月应交58")
else:
    cost=(x-250) *0.25+(y-100)*0.1+(z-50)*0.3
    print("本月应交{}".format(cost))